膜脂在类囊体不同功能膜区的分布及其与植物抗寒性的研究

一． 通过对黄瓜类囊体及其基粒片层、间质片层、PS II放氧颗粒和LHC II 复合体脂类成分的分析，得 到以下结果：各膜区均含有类囊体膜的五种脂类成分，在类囊体及其基粒片层、间质片层和PS II放氧颗粒中，MGDG含量最高，分别为42.5%、40.5%、46.3%、和35.7%，其次是DGDG，含量在31-35%之间。值得注意的是黄瓜类囊体间质片层MGDG含量高于基粒片层，而且DGDG/DGDG分子比也较高。这在其它植物材料中还未见报道。在黄瓜LHC II中，PG含量最高，为35.5%，约是类囊体膜PG含量的3倍。从基粒片层、PS II放氧颗粒到LHC II， PG含量呈逐渐增加的趋势，而在间质片层中，PG含量最低。SQDG除在LHC II中含量稍低外，在其它膜区中的分布没有明显的差异。脂类脂肪酸组成分析结果表明：MGDG主要含亚麻酸，含量在90%以上。DGDG也主要含亚麻酸，含量在90%左右，DGDG所含棕榈酸多于MGDG中的含量。SQDG中主要脂肪酸组分为棕榈酸和亚麻酸。不同膜区MGDG、DGDG和SQDG脂肪酸组成没有明显差异在PG中含量最高的脂肪酸是叶绿体特有的反式十六碳一烯酸（trans-16:1)。此外，PG还含有较多的棕榈酸、硬脂酸和油酸。在不同膜区PG的脂肪酸组成有较明显的差异。 根据以上结果，我们推测脂类除了形成膜的流动性基质外，还可能选择性地结合在膜蛋白周转形成特 异的脂质微区，通过膜脂膜蛋白的相互作用，以行使其特殊的生理功能。 二、通过比较两种不同抗寒性小麦品种在低温锻炼前后类囊体脂类及其脂肪酸成分、LHC II复合体及类囊体吸收光谱、低温荧光发射光谱，发现经低温锻炼后：（1）抗寒与不抗寒小麦品种类囊体PG的trans-16:1含量均明显降低，抗寒品种类囊体MGDG/DGDG比值也明显降低，而不抗寒品种这一比值变化不明显。（2）抗寒品种脂/色素比值明显增高，而不抗寒品种滑明显增加。（3）抗寒与不抗寒品种LHC II宏聚体含量均降低而单体含量增加。（4）抗寒与不抗寒品种类囊体吸收光谱四阶导数光谱A_(683)/A_(652)比值均升高。（5）不抗寒品种低温荧光发射光谱F_(685)/F_(738)比值上升，而抗寒品种这一比值没有变化。通过对上述结果的分析，我们认为低温锻炼过程中类囊体膜流动性增强是使抗寒品种抗寒力增强的主要原因之一，此外，MGDG含量降低对膜的稳定性可能起重要作用。trans-16:1含量的降低和LHC II寡聚体解聚可能是植物对于低温的一种适应性反应。

羧甲基壳聚糖季铵盐作为吸湿保湿剂的应用

本发明涉及化妆品领域，具体讲是一种羧甲基壳聚糖季铵盐作为吸湿保湿剂的应用。所述羧甲基壳聚糖季铵盐为N，N，N，-三甲基羧甲基壳聚糖季铵盐、N-乙基-N，N-二甲基羧甲基壳聚糖季铵盐、N-丙基-N，N-二甲基羧甲基壳聚糖季铵盐、N-正丁基-N，N-二甲基羧甲基壳聚糖季铵盐、N-异丁基 -N，N-二甲基羧甲基壳聚糖季铵盐、N-苯基-N，N-二甲基羧甲基壳聚糖季铵盐或N-水杨醛基-N，N-二甲基羧甲基壳聚糖季铵盐。本发明的吸湿保湿剂具有季铵盐基和羧甲基两类活性基团，吸湿保湿性能远远高于壳聚糖，同时优于透明质酸，而且，壳聚糖价格低廉，市场价格远远低于透明质酸，是一种成本低性能好的吸湿保湿剂。

蛙虹彩病毒cop基因的克隆表达及亚细胞定位

从蛙虹彩病毒(Rana gryliovirus,RGV)基因组中克隆了含凋亡相关结构域的新基因-cop(Caspaserecruit ment domain only protein,COP)基因的全部编码区,成功构建了重组表达载体,进行了原核表达,并在鲤鱼上皮瘤细胞(Epithelioma papulosumcyprini,EPC)中进行了亚细胞定位.序列分析表明,RGVcop基因全长288 bp,编码一个长为95 aa,分子量为10.4×103的推定蛋白.二级结构预测表明其含有5个α螺旋.同源性比对分

香溪河附石性大型底栖动物功能摄食类群研究

利用1∶50 000地形图对香溪河进行划分,显示香溪河为一条6级河流。分析包括捕食者(PR)、撕食者(SH)、刮食者(SC)、直接收集者(GC)和过滤收集者(FC)在内的5个主要功能摄食类群的组成,发现香溪河主要摄食类群以直接收集者和刮食者为主。各功能摄食类群的密度和生物量随着河流级别的变化而发生变化,基本趋势为:直接收集者和滤食者的密度和生物量都随着河流级别的增加而增大;撕食者和刮食者的密度和生物量的密度随着河流级别的增加而减小;而捕食者在整个流域内的密度上游小于下游,生物量却是上游大于下游。研究结果表

三个鲫品系DNA含量的比较研究

采用流式细胞术 (FCM)对红鲫、彭泽鲫、异育银鲫进行红血球DNA含量的检测分析比较 ,以鉴定它们的倍性。结果显示 ,红鲫红血球的DNA含量是 3 0pg ,彭泽鲫是 4 7pg ,异育银鲫是 4 8pg。显而易见 ,彭泽鲫的DNA含量是二倍体红鲫的 1 57倍 ,异育银鲫的DNA含量是红鲫的 1 6倍。采用肾细胞直接制作染色体的方法进行红鲫、彭泽鲫、异育银鲫的染色体倍性鉴定 ,结果红鲫的染色体数目是 10 0 ,为二倍体 (2n =10 0 ) ,彭泽鲫的染色体数目是 162 ,为三倍体 (3n =16

Plankton community composition in the Three Gorges Reservoir Region revealed by PCR-DGGE and its relationships with environmental factors

To explore the relationships between community composition and the environment in a reservoir ecosystem, plankton communities from the Three Gorges Reservoir Region were studied by PCR-denaturing gradient gel electrophoresis fingerprinting. Bacterial and eukaryotic operational taxonomic units (OTUs), generated by DGGE analysis of the PCR-amplified 16S and 18S rRNA genes, were used as surrogates for the dominant "biodiversity units". OTU composition among the sites was heterogeneous; 46.7% of the total bacteria] OTUs (45) and 64.1% of the eukaryotic OTUs (39) were identified in less than half of the sampling sites. Unweighted pair group method with arithmetic averages (UPGMA) clustering of the OTUs suggested that the plankton communities in the Xiangxi Rive sites were not always significantly different from those from the Yangtze River sites, despite clear differences in their environmental characterizations. Canonical correspondence analysis (CCA) was applied to further investigate the relationships between OTU composition and the environmental factors. The first two CCA ordination axes suggested that the bacterial community composition was primarily correlated with the variables of NO3--N, dissolved oxygen (DO), and SiO32--Si, whereas, the eukaryotic community was mainly correlated with the concentrations of DO, PO43--P, and SiO32--Si.

Monitoring bioaccumulation and toxic effects of hexachlorobenzene using the polyurethane foam unit method in the microbial communities of the Fuhe River, Wuhan

Hexachlorobenzene (HCB) is a chlorinated aromatic hydrocarbon that was widely used for seed dressing in prevention of fungal growth on crops, and also as a component of fireworks, ammunition, and synthetic rubbers. Because of its resistance to degradation and mobility, HCB is widely distributed throughout the environment and is accumulated through food chains in different ecosystems. In this study, a preliminary investigation was carried out on the bioaccumulation and the toxic effects of HCB in the microbial (protozoan in particular) communities in the Fuhe River, Wuhan, a water body receiving industrial wastewaters containing HCB and other pollutants, using the standardized polyurethane foam units (PFU) method. Field samples were taken from eight stations established along the Fuhe River in January and August 2006. The concentration ratios of HCB in microbial communities and in water were 9.66-18.64, and the microbial communities accumulated 13.29-56.88 mu g/L of HCB in January and 0.82-10.25 mu g/L HCB in August. Correlation analysis showed a negative correlation between the HCB contents in the microbial assemblage, and the number of species and the diversity index of the protozoan communities. This study demonstrated the applicability of the PFU method in monitoring the effects of HCB on the level of microbial communities.

Structure tuning of line-defect waveguides based on silicon-on-insulator photonic crystal slabs

We present fabrication and experimental measurement of a series of photonic crystal waveguides. The complete devices consist of an injector taper down from 3 mu m into a triangular-lattice air-hole single-line-defect waveguide with lattice constant from 410nm to 470nm and normalized radius 0.31. We fabricate these devices on a siliconon-insulator substrate and characterize them using a tunable laser source over a wavelength range from 1510nm to 1640nm. A sharp attenuation at photonic crystal waveguide mode edge is observed for most structures. The edge of guided band is shifted about 30nm with the 10nm increase of the lattice constant. We obtain high-efficiency light propagation and broad flat spectrum response of the photonic crystal waveguides.

一个支持可信主体特权最小化的多级安全模型

对已有多级安全模型的可信主体支持进行回顾和分析,提出了DLS(离散标记序列)多级安全模型.该模型将可信主体的生命周期分解为一系列非可信状态,对每一个状态赋予一个敏感标记.可信主体的当前敏感标记等于当前非可信状态的敏感标记,非可信状态的切换由预定义的可信请求事件触发.从而可信主体的当前敏感标记可以根据其应用逻辑而动态调整.同时给出了模型保持系统安全性的安全状态和规则.与Bell模型等可信主体敏感标记范围模型相比,该模型在多级安全的策略范围内实现了可信主体的特权最小化.

Partial oxidation reforming of biomass fuel gas over nickel-based monolithic catalyst with naphthalene as model compound

With naphthalene as biomass tar model compound, partial oxidation reforming (with addition of O-2) and dry reforming of biomass fuel gas were investigated over nickel-based monoliths at the same conditions. The results showed that both processes had excellent performance in upgrading biomass raw fuel gas. Above 99% of naphthalene was converted into synthesis gases (H-2+CO). About 2.8 wt% of coke deposition was detected on the catalyst surface for dry reforming process at 750 degrees C during 108 h lifetime test. However, no Coke deposition was detected for partial oxidation reforming process, which indicated that addition of O-2 can effectively prohibit the coke formation. O-2 Can also increase the CH4 conversion and H-2/CO ratio of the producer gas. The average conversion of CH4 in dry and partial oxidation reforming process was 92% and 95%, respectively. The average H-2/CO ratio increased from 0.95 to 1.1 with the addition of O-2, which was suitable to be used as synthesis gas for dimethyl ether (DME) synthesis.